Abstract: Due to complex geological conditions in deep-incised river basins of Southwest China, route selection faces significant geological challenges. This study investigated a road reconstruction project in Tianquan as a case study for disaster-reduction-oriented route planning. A new method for classifying channel development stages—the RCES(River Channel Evolution Stage)approach—was proposed based on threshold hillslope analysis. Integrated with RCES,the normalized stream gradient index(SL/K)and hypsometric integral(HI)were used to generate landscape stability maps for sub-basins along the proposed routes. These maps were combined with spatial disaster distribution analysis to evaluate three alternative route schemes. The results demonstrate that RCES improves the accuracy of identifying the number and clustered distribution of geological hazards compared to previous methods. Route selection should prioritize sub-basins with high landscape stability, avoid high-hazard areas, and traverse zones with low disaster density. These findings provide important scientific support for disaster-reduction-oriented route selection in mountainous and riverine regions.